With the rapid development of smartphones, an increasing quantity of mobile communications terminals are each integrated with a wireless local area network (WLAN, Wireless Local Area Network) communications module. On the other hand, as people continuously increase a requirement for mobile broadband, an existing (such as, wireless cellular) communications system is under a pressure of an increasing quantity of data traffic. A feasible method is: a wireless cellular technology and a WLAN technology are fused to each other, and data traffic of a mobile cellular communications system is offloaded by using a WLAN, thereby greatly improving experience of a user of a cellular system.
Currently, a known communications technology is: after user equipment (UE, User Equipment) already accesses an evolved packet core (EPC, Evolved Packet Core) by using a base station, and establishes a packet data network (PDN, Public Data Network) connection by using a packet data network-gateway (PDN-GW, Public Data Network-Gateway), the UE may access the EPC by using, such as, a trusted wireless local area network access network (TWAN, Trusted Wireless Local Area Networks Access Network), and the TWAN may select a PDN-GW to create a PDN connection, thereby implementing mutual fusion of the wireless cellular technology and the WLAN technology.
However, in the technology, because offloading fusion is performed by the EPC, and the base station cannot autonomously determine an offloading policy (for example, whether to perform offloading to a WLAN and specific offloading traffic) according to current data traffic in real time and cannot ensure that a PDN-GW used when a PDN connection is established by using the WLAN is the same as a PDN-GW used when a PDN connection is established by using the base station, service continuity cannot be ensured, which severely affects user experience.
Therefore, it is intended to provide a technology that can make a base station autonomously determine an offloading policy, and improve user experience.